First time on the forum - looking to do a mileage run from YVR on Air Canada preferred - Star Alliance

Preferred date to leave Dec 15 or 16 - need 12k miles to SElite. Any thoughts? Am I a better to do a quick hop to LHR or FRA and turnaround and then another local trip to make up the difference or just go for it and do a quick turnaround to China or Japan -Australia is to expensive now.
Tx
M4MGUY